Hydrogen separation from synthesis gas near stp

ABSTRACT

A hydrogen separation system and membrane is described for extracting hydrogen from gasifier streams at near atmospheric pressure and ambient temperature conditions. The system can be inserted between a small gasifier and an internal combustion engine which runs a genset to optionally co-produce hydrogen and electricity. The hydrogen is used in a number of important industrial processes.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/463,619 filed on Aug. 19, 2014, which claims priority toU.S. Provisional Patent Application No. 61/871,828 filed on Aug. 29,2013, the contents of which are incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

The invention broadly relates to hydrogen separation from synthesis gasnear STP.

BACKGROUND OF THE INVENTION

Hydrogen containing gas mixtures can be obtained by the incompletecombustion of biomass. Devices which support this operation aretypically referred to as gasifiers. During World War II, a large numberof small gasifiers were fabricated and installed on vehicles to providea combustible gas stream to power the vehicle's internal combustionengine from biomass because gasoline was difficult to obtain. Today'semphasis on long term sustainability, including reducing carbonfootprint and the increasing cost of fossil oil, is renewing interest inthese gasifier-engine systems.

A typical small gasifier-engine combination operates by drawing airthrough the gasifier via the partial vacuum created in the engine'sintake manifold. A range of parameters can be adjusted to supply a widerange of gasses to the engine. The gas stream will typically includenitrogen, carbon monoxide, hydrogen, carbon dioxide, and water vapor.The carbon monoxide and hydrogen are combustible, while the other gassesare diluents which generally reduce engine performance. Operating thegasifier with a high temperature in its char reducing region andsupplying it with sufficient water will result in relatively highhydrogen concentrations, with very little water or carbon dioxide. Forexample, a gas stream including 30% nitrogen, 30% carbon monoxide and30% hydrogen is possible.

Hydrogen has a wide variety of commercial uses beyond running the localengine. As such, it may be desirable to divert some of this hydrogen inconcentrated form for other processes such as: (i) to hydrogenatebiomass to liquid fuels, (ii) to make ammonia as a precursor tofertilizers, (iii) to provide a safe cooking and heating fuel for thedeveloping world, and (iv) to power fuel cell and hydrogen compatibleengines (the classic hydrogen economy).

SUMMARY OF THE INVENTION

Embodiments of the invention are directed toward hydrogen separationfrom synthesis gas near STP.

One embodiment of the invention is directed toward a hydrogen extractionand concentration system which can be inserted between a gasifier and anengine to divert some of its hydrogen while still maintaining acombustible gas stream to fuel the local engine. The hydrogenconcentrator for concentrating the hydrogen stream comprises a filter, apump, a membrane and a hydrogen compressor, wherein the membranecomprises a permselective membrane for permeating hydrogen from the gasstream.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a system and method for extractinghydrogen from a gas stream between a small downdraft gasifier and itsassociated engine.

FIG. 2 is a diagram illustrating a permselective membrane that can beemployed in the hydrogen concentrator illustrated in FIG. 1 in order topermeate hydrogen from the gas stream.

FIG. 3 is a diagram illustrating four generally recognized mechanisms bywhich such a membrane can operate.

FIG. 4 is a diagram illustrating two basic types of carbon includinggraphitized carbon and non-graphitized carbon.

FIG. 5 is a diagram illustrating the structure of hexagonal graphite.

FIG. 6 is a diagram illustrating possible defective carbonaceousstructures.

FIG. 7 is a diagram illustrating a sample defect in a carbonaceousstructure.

FIG. 8 is a diagram illustrating how hydrogen separated using the systemof FIG. 1 can be used directly in various industrial processes orcombined with other substances to make important industrial products.

DETAILED DESCRIPTION

In the following paragraphs, embodiments of the present invention willbe described in detail by way of example with reference to the attacheddrawings. Throughout this description, the preferred embodiment andexamples shown should be considered as exemplars, rather than aslimitations on the present invention. As used herein, the “presentinvention” refers to any one of the embodiments of the inventiondescribed herein, and any equivalents. Furthermore, reference to variousfeature(s) of the “present invention” throughout this document does notmean that all claimed embodiments or methods must include the referencedfeature(s).

Embodiments of the invention are directed toward a hydrogen separationmembrane and a system to extract hydrogen from a synthesis gas stream.

Referring to FIG. 1, one embodiment of the invention involves a system100 and method for extracting hydrogen from a gas stream between a smalldowndraft gasifier 110 and its associated engine genset 120. By way ofexample, the engine genset 120 can include an engine used to run agenerator and make electricity. In this embodiment, the gasifier 110and/or engine genset 120 can be configured and commanded to produce ahydrogen stream while simultaneously producing electricity at a reducedoutput. The hydrogen stream from the gasifier 110 can be filtered usingfilter 115 before it is passed to the engine genset 120 or diverted to ahydrogen concentrator 130 by way of a bypass valve 125. As illustrated,the system 100 includes a hydrogen concentrator 130 comprises a filter140, a pump 145, a membrane 150 and a hydrogen compressor 155. Themembrane 150 in the hydrogen concentrator 130 is designed to concentratehydrogen at low membrane cost and with minimal pumping energy in orderto minimize the cost of the generated hydrogen (including minimizing theuse of electricity for its production).

FIG. 2 is a diagram 200 illustrating a permselective membrane 150 thatcan be employed in the hydrogen concentrator 130 illustrated in FIG. 1in order to permeate hydrogen (depicted by arrow 205) from the gasstream (depicted by arrow 200). This results in a hydrogen depletedretentate (depicted by arrow 220).

FIG. 3 is a diagram 300 illustrating four generally recognizedmechanisms by which such a membrane 150 can operate. Such mechanismsinclude a viscous flow 310, Knudson diffusion 320, molecular sieving330, and solution diffusion 340. Embodiments of the invention utilize anovel combination of processed carbons with a TEFLON binder and an openmesh supporting substrate to provide a membrane 150 which utilizes allfour mechanisms 310, 320, 330, 340 of FIG. 3 simultaneously.

FIG. 4 is a diagram 400 illustrating two basic types of carbon includinggraphitized carbon 410 and non-graphitized carbon 420. Graphitizedcarbon 410 is very dense and offers a very low permeability to gasses.On the other hand, non-graphitized carbon 420 includes both amorphousphases and graphite planes.

FIG. 5 is a diagram 500 depicting the structure of hexagonal graphite.The illustrated graphite planes, referred to as “graphene” layers 510,are capable of providing very small nanopores which can differentiatebetween various gas molecules. Table 1 (below) outlines the kineticdiameters of some relevant gasses.

TABLE 1 Gas Hydrogen Carbon Dioxide Nitrogen Carbon Monoxide Diameter,2.60 3.30 3.64 3.76 Angstroms

FIG. 6 is a diagram 600 illustrating possible defective carbonaceousstructures which, when interconnected, create microporosity. Dependingon the source of the carbon and how it has been processed, acarbonaceous structure can include defects within the graphene planes.The diagram 600 depicts porosity 610 between defective graphene layersand adsorption sites 620 with different adsorption potentials.

FIG. 7 is a diagram 700 depicting a sample defect 710 in a carbonaceousstructure. As illustrated, the basic lattice defect 710 in a grapheneplane is about the same size (2.5 angstroms) as a hydrogen molecule andcan therefore provide very high selectivity for hydrogen versus theother gasses in Table 1.

A porosity measurement system such as a Micromeretics ASAP 2020 can beused for Brunauer-Emmett-Teller (BET) analysis with nitrogen gas orcarbon dioxide to determine the effective pore diameter and distributionin stable solids such as carbon powders. Carbon dioxide absorption isuseful down to about 3 angstroms as seen in ZSM-5 zeolites and activatedcarbons. Some activated carbons indicate a large number of pores in the3 angstrom region (which corresponds to FIG. 7 and the hydrogen diameterof Table 1). Per FIGS. 4 and 6, these small diameter pores are thoughtto be present as defects in randomly oriented graphene planes. Carbonprecursors can be pyrolyzed to provide the desired nanopores.Alternatively, several commercially available carbons exhibit variousconcentrations of the desired pore structure. A complication is that aclean carbon surface has a strong affinity for oxygen including carbondioxide and carbon monoxide. As a result, carbons which have beenrecently pyrolyzed can evolve their apparent pore distribution formonths in open air. Alternatively, commercial carbons have typicallybeen aged as part of the supply chain and are also available at very lowcost as compared to a small scale pyrolysis process. Twenty year oldcarbon which was stored in open air was tested with satisfactoryresults. Commercial carbons of interest for this membrane include CabotVulcan and Black Pearls carbons, AkzoNobel Ketjenblack, Norit SX plusand Denka black.

With reference to FIG. 3, there are several diffusion mechanismsrelevant in this situation. In practice, a porosity network must beformed which includes large pores to access the bulk of the membrane,intermediate pores which provide some degree of selectivity for smallmolecules and the highly desirable size specific pores for hydrogen,which can be as thin as one atom thick in a membrane that is more than10⁷ atoms thick.

Bulk graphite has a density of 2, whereas some of these commercialcarbons have apparent densities of only 0.01. In order to create auseful membrane, carbon(s) must be compacted and held in place to form ahierarchical network which statistically involves a significant numberof hydrogen size specific pores (3 angstrom range). One approach is touse colloidal polytetrafluoroethylene (PTFE) as a binder via a processof compression and PTFE sintering to adhere the carbon matrix to thePTFE matrix. Fuel cell electrodes fabricated with this generaltechnology have exhibited stability for decades. The resulting sinteredmembrane has some flexibility, but low tensile strength, so it should befiber and/or screen reinforced. Suitable bulk materials include choppedfiberglass, or carbon fibers and screen substrates such as fiberglass,stainless steel, plated steel, brass, aluminum and various corrosionresistant alloys.

In some embodiments, the active membrane is molded around the screensubstrate. However, this results in variable active thickness because ofthe dislocation of membrane material by the screen. Also water andoxidative gasses can affect the screen-membrane surface interface,particularly if a low corrosion resistance material such as brass oraluminum is used as the substrate. These issues can be overcome byadding a carbon gas diffusion layer around the screen substrate and thenapplying the gas selective membrane to this uniform surface. Suitablematerials for the diffusion layer include highly graphitized carbonswith relatively low surface areas which will retain macro-pores whencompressed during the molding process. Cabot Vulcan XC500 with a surfacearea of about 75 meters²/gram is an example of this type of carbon.

Such PTFE bound carbon membranes can be tuned over a wide range toaccommodate various system constraints and operating cost tradeoffs.Some examples include adjustments for operating pressure such asthickness and distribution of carbon types as well as support screenstrength. Hydrogen purity versus cost can be varied by membraneselectivity which is primarily a function of the distribution of poresizes and connectivity within the membrane. Overall cost is a functionof input materials cost, processing complexity, membrane sizing, and therequired driving pressure gradient for separation. Overall electrodethickness can range from 0.015 inches to 0.1 inches with 0.030 inchestypical for the active hydrogen permselective elements. Much higherthickness is possible if air filter components are incorporated in thesurface of the membrane.

Metal oxides can be beneficially added to carbon electrodes to stabilizethem against oxidation. Likewise, carbon membranes can benefit fromprotective oxide coatings. Such coatings interfere with the surfaceabsorption and subsequent chemisorption of oxygen species in the porestructure. Silver, copper, cobalt, nickel and other metal salts can bechemically or thermally reduced in the carbon matrix and then oxidizedby open air heating and/or normal operation. Such a treatment can extendthe thermal operating range of the membrane by reducing the carbon'soxidation rate. PTFE softening and loss of structural strength becomesan issue above 150° C. Below that temperature, carbon tolerance tooxidation versus desired life expectancy is a key issue.

In some embodiments, the hydrogen extracted via hydrogen separationsystem 100 is sourced from renewable sources, and as such can be used asa renewable input into a variety of important industries, to produceentirely renewable chemicals and to react with non-renewable chemicals.The utility of this approach is that hydrogen is very portable, anduseful in a variety of processes that could benefit from a smallercarbon footprint. The versatility of this approach is illustrated inFIG. 8, which shows how hydrogen separated with the system of FIG. 1 canbe used directly in various industrial processes or combined with othersubstances to make important industrial products.

In the petrochemical industry, hydrogen is required for crude oilrefinements. Hydrogen can be combined with nitrogen in a Haber-Boschprocess to make ammonia and ultimately fertilizers. Hydrogen is reactedwith vegetable oils to produce such food products as margarine andbutter in a hydrogenation step. It is used for producing severalchemical compounds such as chemical acids and bases, and hydrogenperoxide. With the aid of heat, and oxygen in certain instances,hydrogen can be combined with carbon to yield a variety ofpetrochemicals including gasoline, gasoline-components, kerosene, jetfuel, diesel, naphtha, methanol, DME, methane, light gas oil, LPG,vacuum gas oil and oxygenates such as methanol, dimethyl ether, methyltertiary butyl ether (MTBE), and furan.

Hydrogen can be used in electrochemical fuel cells to generateelectricity when reacted with oxygen. Compression of the hydrogen isnormally required when used in fuel cell vehicles. It can also be usedin combustion processes such as powering hydrogen-fueled engines, and asa reducing agent in chemical processes, such as metal smelting.

In some embodiments, the source of the carbon can be the same downdraftgasifier. The carbon can be material that has been previously stored andtreated, as discussed herein. The carbon may otherwise be obtained viaexternal channels, in the form of charcoal pellets, activated carbonpowder or other suitable means.

Example 1

Vulcan XC72R was mixed with DuPont PTFE dispersion (60% solids pluswetting agent) and distilled water at a 1:1:1 ratio. The resulting pastewas rolled onto a 304 stainless steel screen (18×18 mesh, 0.009″ wire).The paste was rolled to 0.13 grams/cm². The resulting wet electrode wasplaced in an inert atmosphere in a high temperature, high pressuresintering press. The temperature was ramped from ambient to 250° C. in90 minutes and then cooled to 80° C. in one hour, before exposing toair. The pressure was ramped from 65 kg/cm² to 100 kg/cm² during theheat up. The resulting membrane is very dense, somewhat flexible, andgenerally durable by laboratory handling standards.

Example 1 Test Results

The membrane of Example 1 was clamped into a permselective membranetester as per Diagram 2. The feed was 50% carbon dioxide and 50%hydrogen at about 0.1 bar above ambient (very lightly pressurized). Thepermeate side was above the membrane and open to air with a massspectrometer sampling probe located 15 cm above the membrane.Selectivity was about 1000× hydrogen/carbon dioxide. Hydrogen flow underthese very mild test conditions was 45 cm³/cm² of membrane surface perminute.

Example 2

A dual layer membrane was fabricated via a similar technique as Example1 with the following exceptions: the base layer next to the substratescreen is a low surface area graphitized carbon similar to Vulcan XC500(older version in lab inventory). The nano-porous layer was fabricatedfrom an acetylene black similar to Denka Black, (older version in labinventory) with a particle diameter in the 40 to 80 nm range. This layerwas doped with 3% silver by weight as silver nitrate aqueous solution inthe mixing process.

Example 2 Test Results

About a 25% improvement in hydrogen flow rate, but with over a 2×increase in manufacturing cost.

Operation of the overall system for extracting hydrogen illustrated inFIG. 1 will now be described. In order to extract hydrogen, thegasifier-engine system 100 is first brought to operating conditions. Thebypass valve 125 is closed, routing the gasifier output through thehydrogen concentrator system 130 and then back to the engine where theremaining carbon monoxide and residual hydrogen is burned as fuel. Themembrane 150 is set up with a feed and a permeate stream as illustratedin FIG. 2. A wide range of configurations are possible without departingfrom the scope of the invention, including stacking membranes 150 withalternate compartments for the feed and permeate or rolling themembranes 150 into tubes in a tube-and-shell configuration. Since themembrane 150 relies on nanopores for operation, additional gas streamfiltering (e.g., using filter 115) may be appropriate to minimizefouling as indicated in FIG. 1.

Pressure management of the system for extracting hydrogen illustrated inFIG. 1 will now be described. The membrane 150 works by flowing gas froma higher pressure to a lower pressure. In the case of mixed gasses, thepartial pressure of hydrogen on the input side will always be slightlyhigher than the permeate side. By way of example, if the input stream is33% hydrogen, and an output stream of hydrogen at room pressure isdesired, the input must be pressurized to at least 3 bar absolute, andsubstantially higher if most of the hydrogen is to be transferred to thepermeate stream. Since the engine normally draws air through thegasifier 110 at slightly below atmospheric pressure, and the gas streamis only partially hydrogen, pressurizing that stream is very energyintensive. However, some configurations of the engine genset 120 rely onturbocharger boosting of the intake manifold to achieve full power. Insuch configurations, the pump 145 specified in FIG. 1 can be thestandard turbocharger intake which can boost the gas pressure in themembrane 150 to 2 bar or more (absolute) on its way to the engine intakeat minimal net increase in pumping energy as compared to the standardturbocharged engine configuration.

In order to extract a high percentage of the input hydrogen stream tothe permeate stream, the hydrogen compressor 155 as indicated in FIG. 1must generate a vacuum, ideally down to 0.1 bar absolute. The system canbe further optimized by dividing the hydrogen separator membrane stackinto two or more compartments. Each compartment's permeate stream can beserviced by its own smaller first stage vacuum pump. The hydrogenconcentration entering the first stack is relatively high, (20 to 40% ormore) such that a significant amount can be extracted with a modestvacuum. As the gas moves to successive compartments, the permeate streammust operate at successively higher vacuums to extract hydrogen. Theoptimal configuration of membrane surface area, compartmentalization andfirst stage pumping can vary widely based on application, and systemeconomics such as desired capital amortization versus operating cost.

Example 3

A gasifier-engine genset with a 100 kW electrical rating is outfittedwith a hydrogen separator system as described here. The enginedisplacement is 6 liters and operates at 1800 RPM with a standard intakecycle every two revolutions, thus, the engine draws 5400 liters ofair/fuel mix per minute. For conventional synthesis gas mixtures, theratio of synthesis gas to input air is about 1:1, so, the enginerequires 2700 liters of gasifier output per minute. The gas streamcontains 30% hydrogen and the separator system is targeting productionof 20 SCFM hydrogen (560 liters/minute) or ⅔ of the available hydrogen.Assuming membrane performance equivalent to Example 1, 40 feet (3.7meters) is arranged as 40 stacked membranes in 2 packs of 20 each, withan inter-membrane spacing ranging from 0.2 to 2 cm. This configurationcan provide up to three times the required hydrogen flow (when new). Theengine is turbo boosted to 2 bar absolute and the permeate stream isserviced by a vacuum pump/compressor with a 0.05 bar absolute limitingvacuum and a 150 SCFM free air rating. The hydrogen compressor drawsunder 10 kW. The system produces 3.4 kg of hydrogen per hour, which hasan energy content of 113 kWh. Thus, the pumping energy is less than 10%of the hydrogen energy produced.

One skilled in the art will appreciate that the present invention can bepracticed by other than the various embodiments and preferredembodiments, which are presented in this description for purposes ofillustration and not of limitation, and the present invention is limitedonly by the claims that follow. It is noted that equivalents for theparticular embodiments discussed in this description may practice theinvention as well.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not of limitation. Likewise, the various diagrams maydepict an example architectural or other configuration for theinvention, which is done to aid in understanding the features andfunctionality that may be included in the invention. The invention isnot restricted to the illustrated example architectures orconfigurations, but the desired features may be implemented using avariety of alternative architectures and configurations. Indeed, it willbe apparent to one of skill in the art how alternative functional,logical or physical partitioning and configurations may be implementedto implement the desired features of the present invention. Also, amultitude of different constituent module names other than thosedepicted herein may be applied to the various partitions. Additionally,with regard to flow diagrams, operational descriptions and methodclaims, the order in which the steps are presented herein shall notmandate that various embodiments be implemented to perform the recitedfunctionality in the same order unless the context dictates otherwise.

Although the invention is described above in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead may beapplied, alone or in various combinations, to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

A group of items linked with the conjunction “and” should not be read asrequiring that each and every one of those items be present in thegrouping, but rather should be read as “and/or” unless expressly statedotherwise. Similarly, a group of items linked with the conjunction “or”should not be read as requiring mutual exclusivity among that group, butrather should also be read as “and/or” unless expressly statedotherwise. Furthermore, although items, elements or components of theinvention may be described or claimed in the singular, the plural iscontemplated to be within the scope thereof unless limitation to thesingular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, may be combined in asingle package or separately maintained and may further be distributedacross multiple locations.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives may be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

1. A system for extracting hydrogen from a gas stream between adowndraft gasifier and an associated engine genset, the systemcomprising: a bypass valve disposed between the gasifier and the enginegenset for routing the gas stream through a hydrogen concentrator; andthe hydrogen concentrator for concentrating the gas stream, the hydrogenconcentrator comprising a filter for filtering the gas stream, a pumpfor pumping the gas stream through the hydrogen concentrator, amembrane, and a hydrogen compressor; wherein the membrane comprises apermselective membrane for permeating hydrogen from the gas stream; andwherein the extracted hydrogen is reacted with non-renewable chemicalsor combined with carbon, oxygen, or nitrogen in the presence of heat toproduce renewable chemicals.
 2. The system of claim 1, wherein therenewable chemicals are combustible fuels selected from the groupconsisting of: gasoline, gasoline components, kerosene, jet fuel,diesel, naphtha, light gas oil, LPG, and vacuum gas oil.
 3. The systemof claim 1, wherein the renewable chemicals are oxygenates selected fromthe group consisting of: methanol, dimethyl ether, methyl tertiary butylether (MTBE), and furan.
 4. The system of claim 1, wherein the renewablechemical is ammonia.
 5. The system of claim 1, wherein the hydrogen isreacted with non-renewable hydrocarbons in a hydrogenation step.
 6. Thesystem of claim 2, wherein the extracted hydrogen is used in apetrochemical refining step.
 7. The system of claim 1, wherein thecarbon is produced using a downdraft gasifier.
 8. The system of claim 7,where in the carbon is biochar.
 9. The system of claim 1, wherein thehydrogen is reacted with oxygen to make electricity in a fuel cell. 10.The system of claim 1, wherein the hydrogen is used to make heat. 11.The system of claim 1, where in the hydrogen is used to make chemicalacids or bases.
 12. A system for extracting hydrogen from a gas streambetween a downdraft gasifier and an associated engine genset, the systemcomprising: a bypass valve disposed between the gasifier and the enginegenset for routing the gas stream through a hydrogen concentrator; andthe hydrogen concentrator for concentrating the gas stream, the hydrogenconcentrator comprising a filter for filtering the gas stream, a pumpfor pumping the gas stream through the hydrogen concentrator, a membraneformed from a bulk carbon which is compressed and held in form bysintered PTFE, and a hydrogen compressor; wherein the membrane comprisesa permselective membrane for permeating hydrogen from the gas stream;and wherein the extracted hydrogen is stored, compressed and used in afuel cell vehicle.